A capillary array electrophoresis apparatus includes, basically, a capillary array having a plurality of capillaries, a power supply for applying a high voltage on both ends of the capillary, an excitation optical system comprising a laser light source or the like, and a photo-receiving optical system for detecting fluorescence. Upon analysis of a sample, a sample such as a fluorescence-labeled DNA is electrophoresed and separated in the order of molecule size, and an irradiation light is applied to the labeled sample to detect emitted fluorescence. The capillary array electrophoresis apparatus provides a high separation speed for samples, can analyze plural samples simultaneously and can meet the demand of analysis such as for DNA and proteins which has been required more and more in recent years.
U.S. Pat. No. 6,562,214 discloses an electrophoresis apparatus in which a capillary array formed by laminating plural capillaries to two sheets are in contact with a heater.